1. Field of the Invention
The present invention relates to a headrest for use in an automotive seat. In particular, the invention is directed to a forward and backward inclination adjustment device for the headrest, which is provided on a generally inverted U-shaped headrest frame and allows the headrest to be inclined forwardly and backwardly relative to such headrest frame.
2. Description of Prior Art
Some of various forward and backward inclination adjustment devices for headrest employs a generally U-shaped leaf spring for adjustment of inclination of the headrest. In that case, the headrest used is typically formed by a headrest body frame and a generally inverted U-shaped headrest frame. The generally inverted U-shaped headrest frame has a horizontal frame section and a pair of vertical frame sections forming a pair of headrest stay portions. The headrest body frame is rotatably connected, via a generally U-shaped leaf spring, with the horizontal frame section, such that the leaf spring gives a resilient pressing force to the horizontal frame section, thereby allowing the headrest body frame to be adjustably inclined forwardly and backwardly relative to the two vertical frame sections or the two headrest stay portions. For example, the U.S. Pat. No. 4,840,428 discloses this kind of headrest structure provided with a pair of leaf springs each having an arcuate portion. According thereto, a headrest body frame is rotatably secured to a horizontal frame section of a generally inverted-U-shaped headrest frame by embracingly attaching the arcuate portions thereof about that horizontal frame section, so that the headrest can be inclined and retained by a desired angle due to a frictional force given by those arcuate portions of leaf springs to the horizontal frame section. Further, a bracket is provided integral with the headrest frame to prevent both two leaf springs against deformation.
However, the foregoing conventional frictional leaf spring arrangement to inclination of headrest merely provides a stepless touch to a user who adjusts the inclination of headrest, and does not provide any clicking stepwise touch to the user who desires that particular controlled touch to recognize each inclination angle of headrest when he or she rotates the headrest in the fore-and-aft direction. Further, when it comes to adding such clicking stepwise touch in the headrest, conventional headrests have a plural number of required elements and parts for that purpose, resulting thus in a complicated and costly structure as well as in an undesired increase of the weight thereof.
In view of the above-stated drawbacks, it is a primary purpose of the present invention to provide an improved forward and backward inclination adjustment device for a headrest, which is structurally simplified and lightweight and further provides a clicking stepwise touch when inclining the headrest.
In order to achieve such purpose, in accordance with the present invention, there is provided a forward and backward inclination adjustment device for headrest, which basically comprises:
a leaf spring means of a generally xe2x80x9cUxe2x80x9d shape, said leaf spring means being firmly secured to said headrest body frame; and
a plurality of discrete flat surfaces formed in said horizontal columnar frame section of said generally inverted-U-shaped frame,
wherein said leaf spring means resiliently holds said horizontal columnar frame section in such a manner that one of said plurality of discrete flat surfaces is normally biased to contact with said leaf spring means, so that, when inclining said headrest body frame in one of said forward and backward directions, a selected one of said plurality of discrete flat surfaces is brought to contact with said leaf spring means, thereby allowing said headrest body frame to be adjustably inclinable with a clicking stepwise touch.
Preferably, the leaf spring means includes a flat portion, so that, when inclining said headrest body frame in said one of said forward and backward directions, said selected one of said plurality of discrete flat surfaces is brought to contact with said flat portion of said leaf spring means, thereby allowing said headrest body frame to be adjustably inclinable with the clicking stepwise touch.